The second way to access the four banks is through Midi control. basically, Twister receives certain midi notes through a predefined midi channel and voila! You have bank change!
And thus, Bang my Twister was born. Developed by Aaron Levitz (The designer behind my Spy Guitar Visualizer) It is a simple device that sends those bank change messages to Twister. Its four buttons accept input from your first four number keys on your qwerty (without having to keymap them!). They are also midi mappable. This of course gives you two ways to change banks (three if you use the side buttons too).
Download it here
Bang my Twister